1. Field of the Invention
The invention relates to a device for the slitting of bark layers and birch-bark layers on logs in order to achieve controlled drying of the wood.
2. Description of the Prior Art
Wood has always been of great importance as fuel and recently, wood has become more important as raw material for the pulp and paper industry. The building industry is an additional important area of use for wood and lumber.
It is very important when using wood as fuel that the wood be as dry as possible when being utilized. In order to speed up the drying process, the wood is, therefore, usually split into logs and stacked for air-drying. The splitting process is time consuming and expensive and the main disadvantage is that the volume of wood increases considerably after the splitting, which makes the transport and storage costs very high.
When using the wood in the pulp industry, the tree trunks are debarked in order to facilitate the drying process and to prevent rotting. As in the splitting process, the debarking is also time consuming and costly. In those cases when the wood is stored unbarked, the remaining high moisture content results in rot and this is especially true if the stored logs consist of hardwood. In the storage of logs with the bark thereon substantially intact for one year with the resulting high moisture content in the wood, up to 10% of the wood would be unusable and the quality of the pulp produced would be poorer.
The logs which are to be sawed into boards, etc., must be seasoned slowly in order to avoid the formation of cracks and, therefore, the bark cannot be completely removed from the trunks before the drying process.